Assigedbto dudley



(No Model.)

T. W. DUFFY.

GAR BRAKE.

Patented June A3, -188 -IEN illlllll UNITED STATES PATENT UEEICE.

THOMAS WM. DUFFY, OFMEDFORD, MASSACHUSETTS, ASSIGNOR TO DUDLEY C. HALL,OF SAME PLACE.

CAR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 299,526, dated .Tune 3,1884-.

Application filed March 19, 1884. (No model.)

.To LZZ zchom it may concern:

Be it known that I, THoMAs WM. DUEEr,of Medford, in the county ofMiddlesex, State of Massachusetts, have invented a certain newl anduseful Improvement in Car-Brakes, ofwhich the following is a descriptionsufficiently full, clear, and exact to enable any person skilled in theart or science to which said invention appertains to make and use thesame,

Io reference beinghad to the accompanying drawings, forming a part ofthis specication, in which- Figure lis a sectional top plan view, andFig. 2 a side elevation showing my improved brake attached to the truckof a car.

Likeletters of reference indicate corresponding parts in the differentfigures of the drawings.

My invention relates to that class of carbrakes known as air or vacuumbrakes; and it consists in a novel construction and arrangement of theparts, as hereinafter more fully set forth and claimed,by which asimpler, cheaper, and more effective device of this character isproduced than is now in ordinary use.

The nature and operation of the improvement will be readily understoodby all conversant with such matters from the following explanation, itsextreme simplicity rendering an elaborate description unnecessary.

In the drawings, A represents the frame of the truck, B B the wheels, CC the boxes, D the yoke, and E E the springs. These parts being allofthe ordinary construction and not herein claimed, when in and ofthemselves considered, itis deemed unnecessary to more particularlydescribe them.

Projecting downwardlyfrom the frame-work A, and securely attachedthereto by the bolts x, there is a cylinder, G. (Represented in Fig. 2with 'one of its sides partially removed.) Disposed within this cylinderthere is apiston, m, provided with a guide-rod, l, and pistonrod I-I,the latter passing through and being fitted to work vertically in a holein the head J. A coiled spring, K, is also disposed'lwithin thecylinder, the upper end of the spring abutting against the lower side ofthe piston, and its lowery end resting on the head J, the spring 5oacting expansively to force the piston upwardly within the cylinder. Thelower end of the piston-rod H terminates in a cross-bar, L, or isT-shaped, as shown in Fig. 2, the bar being provided on its lower sidewith the detachable brake-shoe M, which is secured thereto by bolts z. Adouble or V-shaped brace, N. provided with the vertical slot i, isattached at either side of the cylinder to the under side of theframe-work of the truck, and projecting later- 6o ally from either sideof the bar Lthereis a stud, d, the Astuds being adapted to workvertically in the slots as the piston-rod H rises and falls.

It will be understood that the truck is furnished on either side withone of the cylinders G and two of the braces N, and that the brake-shoesM are so arranged as to be directly over the rails B, on which thetrucks B rest.

In the use of my improvement air is forced into the cylinder G above thepiston m, caus- 7o ing the rod H to descendand press the shoe M upon thetrack, thereby braking or stopping the truck and superposed car (notshown) in a manner which will be readily obvious without a more explicitdescription. When the pressure on the air is withdrawn, or therelief-valve (not shown) is opened, the spring K will act to raise theshoe from the rail or take off the brake. The shoe is curved upwardly ateither end, as seen at f, thereby 8o adapting it to brake the truck orcar equally well when running in either direction.

It will be obvious that the end-thrust of the shoe, caused by itsfrictional contact with the rail, will be resisted by the brace Nandstud d, and that the power necessary to overcome the friction betweenthe shoe and rail will consequently be exerted in braking or stoppingthe truck.

Instead offorcing air into the cylinder above 9o the piston, asdescribed, a vacuum may be formedby withdrawing the air from beneath thepiston and produce substantially the same result.

As the mechanism for forcing air into the cylinder above the piston, orwithdrawing it from below the same, as the case maybe, consists of thepipes, pumps, and other well-known appliances for like purposes incommon use with nearly all ordinary air or vacuum carbrakes, it is notdeemed essential to shonY them in order to a full understanding,` of myiniprovenient.

I do not eonine myself tothe use of the studs d and slots i for engagingthe piston-rod and braces, as other means for the saine purpose may beemployed, if desired, and accomplish the same results. NeitherdoIconiine myself to locating the brake between the wheels of the truck,as shown, as it may be placed centrally beneath the body of the car, orin any other suitable position desired.

Having thus explained my invention, what I claim is- 1, In a car-brakesubstantially such as described, thefollowinginstrumentalities, to wit:an air-cylinder provided with a piston, a pistou-rod connected with saidpiston 1within the cylinder and earryinga brake-shoe at its outer endadapted to engage the rail, a springdisposed within the cylinder andadapted to retract the piston-rod, and abrace, substantially asdescribed, adapted to resist the end-thrust of the brakeshoc when saidshoe is in frietional contact with the rail, in combination withsuitable operative mechanism, substantially as set forth.

2. In a ear-brake substantially such as dcscribed, the cylinder G,provided with the pis ton m and spring K, the rod H, provided with thebar L, shoe M, and stud d, and the braces N, provided with the slots i,constructed, conibined, and arranged to operate substantially asspcciiied.

THOMAS XVM. DUFFY.

Vi tn esses:

Homer; D. Ham., C. D. WMNWmGirr.

